In numerous wellbore environments, a variety of wellbore assemblies are used for well related activities. For example, assemblies may be used in many types of well related procedures, including well stimulation, cementing, water control treatments or other procedures. In many of these well applications, a packer is used to isolate a region of the wellbore in which the desired activity or operation is conducted.
In some applications, cup type downhole packers have been utilized, and in other applications, mechanical or hydraulic packers have been employed. Cup type downhole packers have an elastomeric sealing element designed to seal against a casing wall. However, the elastomeric sealing element is subject to wear due to this contact with the casing wall and/or contact with burrs along the inside of the casing left from the creation of perforations. Cup type packers also are prone to getting lodged in the wellbore, and they present additional problems in horizontal wells due to the natural positioning of the bottom hole assembly on a low side of the hole, leaving uneven clearance on the low side relative to the high side of the hole. Mechanical and hydraulic packers also are subject to wear and damage due to burrs left from casing perforation. Additionally, such packers are more complicated, expensive and prone to failure in a sand laden environment, while offering poor performance in open hole applications.
The use of an inflatable straddle packer can cause significant operational issues such as failing to set, unseating, parting and leaking. The challenges associated with these straddles are depth accuracy, hydraulic setting mechanism in sub-hydrostatic wells and poor tubular condition, tubing movement expansion and contraction of pipe during treatment, and waiting for packer elements to relax, which can cause resources and time in a treatment scenario.
Some packers are currently formed from particulate materials at desired locations in wellbores to isolate particular zones. However, in some applications, the material forming the packer is not readily removable and released after the particular activity is completed. Often, significant fluid pressure and volume is required to remove the packer. Further, in some instances, conventional sand plugs for zonal isolation (as used for proppant fracturing treatments) are not suitable as the sand would have potential to invade the matrix and reduce the permeability.
Thus the need exists for materials and methods of forming and easily removing wellbore packers which isolate wellbore zones.